We would level Russia. Putin didn’t retaliate specifically for this reason.
He didn't retaliate because there wasn't any need to. Putin is highly intelligent. If he wants revenge, he's most likely will use alternative methods to hit back. However, since the US didn't do much outside of destroying what were most likely, empty buildings, Putin may not see the need to do anything.
If you think an all out war with Russia would result in an easy victory though, then you are just showing how ignorant you truly are.